scholarly journals Switching the Conformation of 3,2′:6′,3″-tpy Domains in 4′-(4-n-Alkyloxyphenyl)-3,2′:6′,3″-Terpyridines

Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3162 ◽  
Author(s):  
Dalila Rocco ◽  
Alessandro Prescimone ◽  
Edwin C. Constable ◽  
Catherine E. Housecroft

The preparation and characterization of 4′-(4-n-octyloxyphenyl)-3,2′:6′,3″-terpyridine (8) and 4′-(4-n-nonyloxyphenyl)-3,2′:6′,3″-terpyridine (9) are reported. The single crystal structures of 4′-(4-n-hexyloxyphenyl)-3,2′:6′,3″-terpyridine (6), 4′-(4-n-heptyloxyphenyl)-3,2′:6′,3″-terpyridine (7), and compounds 8 and 9 have been determined. The conformation of the 3,2′:6′,3″-tpy unit is trans,trans in 6 and 7, but switches to cis,trans in 8 and 9. This is associated with significant changes in the packing interactions with a more dominant role for van der Waals interactions between adjacent n-alkyloxy chains and C–Hmethylene... π interactions in 8 and 9. The solid-state structures of 6 and 7 with the n-hexyloxy and n-heptyloxy chains feature interwoven sheets of supramolecular assemblies of molecules, with pairs of n-alkyloxy chains threaded through cavities in an adjacent sheet.

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 325
Author(s):  
Giacomo Manfroni ◽  
Alessandro Prescimone ◽  
Edwin Constable ◽  
Catherine Housecroft

We have prepared and characterized 1,4-dibromo-2,5-bis(2-phenylethoxy)benzene (1) and 1,4-dibromo-2,5-bis(3-phenylpropoxy)benzene (2). Their single-crystal structures confirm that, at the molecular level, they are similar with the phenylalkoxy chains in extended conformations. However, there are significant differences in packing interactions. The packing in 1 is dominated by C–Br...π(arene) interactions, with each Br located over one C–C bond of the central arene ring of an adjacent molecule. In contrast, the packing of molecules of 2 involves a combination of C–H...Br hydrogen bonds, Br...Br interactions, and arene–arene π-stacking. The single-crystal structures of both orthorhombic and triclinic polymorphs of 1 have been determined and the packing interactions are shown to be essentially identical.


Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 182-198
Author(s):  
Dalila Rocco ◽  
Samantha Novak ◽  
Alessandro Prescimone ◽  
Edwin C. Constable ◽  
Catherine E. Housecroft

We report the preparation and characterization of 4′-([1,1′-biphenyl]-4-yl)-3,2′:6′,3″-terpyridine (1), 4′-(4′-fluoro-[1,1′-biphenyl]-4-yl)-3,2′:6′,3″-terpyridine (2), 4′-(4′-chloro-[1,1′-biphenyl]-4-yl)-3,2′:6′,3″-terpyridine (3), 4′-(4′-bromo-[1,1′-biphenyl]-4-yl)-3,2′:6′,3″-terpyridine (4), and 4′-(4′-methyl-[1,1′-biphenyl]-4-yl)-3,2′:6′,3″-terpyridine (5), and their reactions with copper(II) acetate. Single-crystal structures of the [Cu2(μ-OAc)4L]n 1D-coordination polymers with L = 1–5 have been determined, and powder X-ray diffraction confirms that the single crystal structures are representative of the bulk samples. [Cu2(μ-OAc)4(1)]n and [Cu2(μ-OAc)4(2)]n are isostructural, and zigzag polymer chains are present which engage in π-stacking interactions between [1,1′-biphenyl]pyridine units. 1D-chains nest into one another to give 2D-sheets; replacing the peripheral H in 1 by an F substituent in 2 has no effect on the solid-state structure, indicating that bifurcated contacts (H...H for 1 or H...F for 2) are only secondary packing interactions. Upon going from [Cu2(μ-OAc)4(1)]n and [Cu2(μ-OAc)4(2)]n to [Cu2(μ-OAc)4(3)]n, [Cu2(μ-OAc)4(4)]n, and [Cu2(μ-OAc)4(5)]n·nMeOH, the increased steric demands of the Cl, Br, or Me substituent induces a switch in the conformation of the 3,2′:6′,3″-tpy metal-binding domain, and a concomitant change in dominant packing interactions to py–py and py–biphenyl face-to-face π-stacking. The study underlines how the 3,2′:6′,3″-tpy domain can adapt to different steric demands of substituents through its conformational flexibility.


1992 ◽  
Vol 70 (3) ◽  
pp. 919-925 ◽  
Author(s):  
A. Wallace Cordes ◽  
Charles M. Chamchoumis ◽  
Robin G. Hicks ◽  
Richard T. Oakley ◽  
Kelly M. Young ◽  
...  

The preparation and solid state characterization of the bifunctional radical furan-2,5-bis(1,2,3,5-dithiadiazolyl) 2,5-[(S2N2C)OC4H2(CN2S2)] and the related monofunctional radical 2-cyanofuran-5-(1,2,3,5-dithiadiazolyl) 2,5-[(S2N2C)OC4H2(CN)] are described. The crystal structure of 2,5-[(S2N2C)OC4H2(CN2S2)] is orthorhombic, space group Pna21, and consists of interleaved arrays of dimers, for which the mean interannular [Formula: see text] contact is 3.137 Å. The crystal structure of the monofunctional radical 2,5-[(S2N2C)OC4H2(CN)] is monoclinic, space group P21/n, and consists of a ribbon-like network of dimers (mean interannular [Formula: see text] interconnected by close head-to-tail [Formula: see text] contacts. The dimer units form stacks parallel to z, with a mean interdimer [Formula: see text] separation of 3.956 Å. The similarities and differences between these two crystal structures and those of related benzene-substituted systems are discussed. Keywords: dithiadiazolyl radicals, furan-based diradicals, cyanofuran-based radicals, radical dimers, crystal structures.


Polyhedron ◽  
2000 ◽  
Vol 19 (15) ◽  
pp. 1803-1807 ◽  
Author(s):  
Inamur Rahaman Laskar ◽  
Tapas Kumar Maji ◽  
Siddhartha Chaudhuri ◽  
Ashutosh Ghosh ◽  
Nirmalendu Ray Chaudhuri

2021 ◽  
Author(s):  
Filip Topic ◽  
Joseph Marrett ◽  
Tristan Borchers ◽  
Hatem M. Titi ◽  
Christopher J. Barrett ◽  
...  

<div>We report the first single crystal structures of hypochlorite and hypobromite salts, including hydrated sodium hypochlorite - a ubiquitous bleaching and disinfection agent in use for almost 200 years. The structures represent the first characterization of fundamentally important hypochlorite and hypobromite anions in the solid state, by X-ray crystallography and are supported by Raman spectroscopy on individual crystals. The structural analysis provides insight into supramolecular chemistry of the hypohalite ions in the hydrated environment of the NaOCl<sup>.</sup>5H<sub>2</sub>O and NaOBr<sup>.</sup>5H<sub>2</sub>O solid salts, and reveals measured Cl-O and Br-O bond lengths of 1.69 A and 1.82 A, respectively, which are significantly longer than those for corresponding higher-valence oxoanions, and in agreement with the values spectroscopically determined for hypohalous acids and corresponding oxides in the gas phase.<br></div>


2014 ◽  
Vol 67 (7) ◽  
pp. 1005 ◽  
Author(s):  
Dan Dumitrescu ◽  
Yves-Marie Legrand ◽  
Nathalie Masquelez ◽  
Arie van der Lee ◽  
Mihail Barboiu

Four single crystal structures were obtained in order to better understand the difference between the crystallisation-driven formation of solid state organo-sulfonate guanidinium superstructures and their sodium salt analogues. 5-Formyl-2-furfuryl sulfonate and 4,4′-diamino-2,2′-biphenyl disulfonate were chosen as anions due to functional and geometrical considerations together with guanidinium, aminoguanidinium, and sodium cations. 5-Formyl-2-fufuryl sulfonate reacts with aminoguanidinium cation in water leading to an imino-zwitterionic compound, able to form on its own a guanidinium-sulfonate superstructure in crystalline state.


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